Over the past year and rise in data breaches, hackers have always targeted high-prized targets, including government servers, health care branches and even retailers, this year, hackers took another turn, hitting an adult dating site leaking the sexual secrets of millions.

Nearly four million registered users have had their personal information leaked online. Hackers stole email addresses, usernames, dates of birth, postal codes, and IP addresses, where all the information is currently for sale on the dark web.

News of the Adult Friend Finder breach broke Thursday, warning users of the California-based dating site with over 63 million registered members.

Hackers breached the adult dating site database, stealing information on all sexual orientations and dating/affair-style relations. Access to such information could lead to blackmail or financial extortion Channel 4 news reported, citing brief cases hinting such is already occurring.

One man, Shaun Harper, had his information leaked in the Adult Friend Finder breach, being notified even after he had already deleted his account. Pointing out that the adult dating site does not purge information even after the user has requested deletion. This could put more than 64 million users at risk, but Channel 4 thus far has said only a small portion, four million users, have been affected.

At the moment, no hacking group has taken credit for the hack, but the breach is defiantly alarming, seeing as millions could have their secret sex life exposed by one single breach. One hacker with a forum username ROR[RG] was found leaking the information on the dark web, but information this far is scarce.

Cybercrime experts have warned users of blackmail, stating with the amount of information hackers stole, extortion and blackmail will be targeted towards registered users whose secrets have been exposed. A number of Adult Friend Finder members have already confirmed their emails have been targeted with large amounts of spam.

Following the information being leaked publicly online, dozens of spam campaigns rolled over the coming days, now allowing experts to sift through the data and identify potential targets. Leaked spreadsheets exposed the confidential information of government and armed service personnel, including information on the British Army.

FriendFinder Networks, parent company of Adult Friend Finder, confirmed the data breach, but held back details regarding the scope of the attack. The company withheld numbers stating they are currently under investigation with law enforcement agencies.

“FriendFinder Networks Inc. understands and fully appreciates the seriousness of the issue,” the network said in a statement. “We have already begun working closely with law enforcement and have launched a comprehensive investigation with the help of leading third-party forensics expert. We pledge to take the appropriate steps needed to protect our customers if they are affected.”